Dave McClure asked his “Facebook As A Platform” panelists — SocialMedia’s Seth Goldstein, iLike’s Ali Partovi, Slide’s Keith Rabois, and RockYou’s Lance Tokuda — to comment on Kara Swisher’s suggestion that all the Facebook apps are useless. At her site today, she says “To these folks, ‘silly, useless and time-wasting’ is apparently a business model.”

Some persuasive evidence by the panelists that a business model is developing fast:

Slide’s Rabois reminded us that several other useless and time-wasting industries — music, movies, TV and watching sports — add up to about a trillion dollars in revenues, if taken together.

iLike’s Partovi said his company’s music app for Facebook, just four months into its existence, currently drives more traffic to iTunes than any other source and is the #3 traffic source for Ticketmaster. Gotta be some money there.

I had dinner last night with another Facebook apps player, Graffiti Wall’s Mark Kantor. Graffiti has 8 million users so far, and FM works with them to explore advertiser interest. So far, so good. Yesterday HP’s Imaging and Printing Group announced the launch of a new a partnership with Graffiti. Others have already signed contracts; I won’t share names since the campaigns haven’t yet launched. We teamed up with Graffiti less than a month ago, though, it’s my guess that they’ll be a profitable company starting next month.

I was on a panel this morning with Mary Hodder of Dabble and Susan Bratton of Personal Life Media, discussing revenue models for online video and audio. Stat from Mary: Each day 300,000 new video files are uploaded to the web. Stat from Ask A Ninja’s Kent Nichols: In August 07, there were 9.7 billion searches and 9.1 billion video views. Wow, that’s something to think about. Someone asked me how much money we’re all talking about; I said we should start by taking that $5 billion (3% of $162 billion in US TV spend) that Nielsen just announced is wasted because no one is watching. After that, we should take a look at the other $157 billion. Hey, maybe Nielsen is being generous to the networks.